This invention relates to the field of robotics, specifically how robots can aid humans in transporting heavy loads over rough terrain.
The task of transporting heavy objects over rough terrain has previously been solved by the use of wheeled and treaded vehicles. These vehicles include jeeps, motorcycles, tanks, and All-Terrain-Vehicles (ATV). The limitations of these devices are the types of terrain that they can operate on, and their maneuverability on that terrain. On roads or other relatively smooth terrain, these devices are successful. But when the terrain is very irregular, as in jungles, these devices become useless. Another limitation of these devices is due to their size. The size problem has been solved by a class of inventions called motorized wheelbarrows and carts (as in U.S. Pat. Nos. 5,465,801; 5,284,218; 5,211,254; and 4,811,988). These inventions all use wheels as the means to contact the ground and provide the locomotion. On smooth roads, wheel devices provide suitable means for locomotion. On very rough and irregular terrain wheeled devices consume a significant amount of power, provide poor ride quality, damage the terrain, and encounter problems with traction. Often, these wheeled devices cannot even traverse the rough terrain.
The solution to providing means for locomotion on rough and irregular terrain comes from legged robots and machines. Legged versus wheeled locomotion has the advantages of requiring less energy, attaining higher speeds, greater mobility, better isolation from terrain irregularities, and less environmental damage (Bekker 1960; Song and Waldron 1989). The problem with having legged machines navigate through rough terrain is the technology is such that it cannot support a fully autonomous legged machine. A few six-legged machines have been built that can walk on irregular terrain (Adaptive Suspension Vehicle built by Ohio State University, Song and Walkron 1989; MECANT I, Hartikainen et. al 1992) but they are large, bulky, and move slowly.